1300-50;Middle Englishadversarie < Latinadversārius, equivalent to advers(us) (see adverse) + -ārius-ary; replacing Middle Englishadversere < Anglo-French
1. Adversary, antagonist mean a person or a group contending against another. Adversary suggests an enemy who fights determinedly, continuously, and relentlessly: a formidable adversary. Antagonist suggests one who, in hostile spirit, opposes another, often in a particular contest or struggle: a duel with an antagonist.
early 14c., aduersere, from Anglo-Fr. adverser (13c.), from O.Fr. adversier, from L. adversarius "opponent, adversary, rival," lit. "turned toward one," from adversus "turned against" (see adverse). The L. word is glossed in O.E. by wiðerbroca. The adj. adversarial is attested from 1970 and probably was coined to avoid confusion which might arise with use of adversary (adj.), which is attested from late 14c.
(Heb. satan), an opponent or foe (1 Kings 5:4; 11:14, 23, 25; Luke 13:17); one that speaks against another, a complainant (Matt. 5:25; Luke 12:58); an enemy (Luke 18:3), and specially the devil (1 Pet. 5:8).